Put those sts on yarn or something flexible so they sort of 'fold up' and you can bring the next set of sts right next to the first set to work them. Or you can CO 2 sts to bridge that gap a little, then dec them on the next round.

For the thumb - Put the 10 held sts onto dpns. Knit them and pick up sts in that gap where you put the sts on a holder. You can do something like a m1 in the sts next to the gap, or if you CO 2 sts, pick 2 up from them and one before and after them. So you have 14 sts and on the next round you're going to dec the 4 extra down to 12. Then knit until the thumb is the length you want.

That will make a thumb hole? I feel like if I put the stitches on yarn to hold them, then knit the next stitches, it folds up the ones that were set aside on the yarn and just knits like... behind them, and will close the hole. It's just hard for me to visualize this whole thing.

You're making a thumb hole 10 sts across, the sts you knit before and after the ones on the holder are for the hand part. The 10 sts leave a hole, you can CO 2 more like I said and dec them on the hand and dec them if that's going to make the hand too loose. You'll see how it works when you get there.

I did not look at the pattern now, but if 10 stitches in that pattern are enough to make it around the thumb, then it is as suzee said - she is right almost any time anyways!

If the thumb will have more than 10 stitches to go around: where does the pattern want you to get them from? Pick them up on the bridge? Maybe. I'd have to look.

I have made most my gloves in the past by putting the stitches for 1/2 thumbround on a holder after knitting them for that round. Then on the following round I have cast on enough stitches to replace that spot and later picked up the corresponding number of stitches from that bridge and maybe 2 extra for the gaps to close the holes. But if your pattern has a "designated amount of stitches" for the thumb: then you just work as said by suzee.

Imagine to hold a plastic bag and now you put a paper clip on one side, leaving a little of the bag to one side and most to the other: That opens up a seperate hole you can put a finger through. That is most likely what you shall do. Then continue up for the rest of the palm and the other fingers.

The pattern says to pick up an extra 4 sts in the gap when you begin to work the thumb, then dec 2 of them on the first round leaving you with 12. I suggested a CO of 2 sts for the bridge, then dec on the hand if needed, but pick up 2 in them and another 2 on either side to get the 14 sts the thumb starts with.